This invention relates in general to beds and in particular, to high/low beds, which are beds that are adapted to be raised and lowered relative to a supporting support, such as a floor. Most particularly, the invention relates to a linkage assembly for high/low beds.
High/low beds are well known. A conventional high/low bed includes a sleep surface supported by a main frame. The main frame is supported by a pair of opposing legs (i.e., legs at opposite ends of the main frame). The sleep surface often includes a head section, a foot section, and a knee section between the head and foot sections. The head and knee sections are pivotally supported by a main frame so that they may be raised and lowered relative to the main frame. The foot section is pivotally connected to the knee section so that it moves in response to movement of the knee section. In addition to the sleep surface being movable, the legs of the bed are movable. Movement of the legs changes the position of the main frame relative to a supporting surface (i.e., a floor or the ground) by raising or lowering the main frame.
The physical structure of the high/low bed often limits its ability to achieve desired minimum and maximum elevations. For example, forces acting upon the legs are greatest when the bed first begins to rise from its lowest position. These forces resist movement of the legs if the angular disposition of the legs is too great. As the legs come closer to being horizontal, when the bed is in its lowered position, a greater amount of force is required to start the legs in motion to raise the bed. The force can become so great that a cost-effective mechanical means for displacing the legs could be ineffective.
What is needed is a high/low bed having an elevation that is minimized when in a lowered position and that has a cost-effective mechanical means for raising the bed from its lowered position.